Use a single NetworkEndpoint per NIC per protocol

The NetworkEndpoint does not need to be created for each address.
Most of the work the NetworkEndpoint does is address agnostic.

PiperOrigin-RevId: 326759605

2 files changed, 6 insertions, 21 deletions

diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go
index 067d770f3..b5659a36b 100644
--- a/pkg/tcpip/network/ipv4/icmp.go
+++ b/pkg/tcpip/network/ipv4/icmp.go
@@ -37,8 +37,9 @@ func (e *endpoint) handleControl(typ stack.ControlType, extra uint32, pkt *stack
 	// false.
 	//
 	// Drop packet if it doesn't have the basic IPv4 header or if the
-	// original source address doesn't match the endpoint's address.
-	if hdr.SourceAddress() != e.id.LocalAddress {
+	// original source address doesn't match an address we own.
+	src := hdr.SourceAddress()
+	if e.stack.CheckLocalAddress(e.NICID(), ProtocolNumber, src) == 0 {
 		return
 	}
 
@@ -53,7 +54,7 @@ func (e *endpoint) handleControl(typ stack.ControlType, extra uint32, pkt *stack
 	// Skip the ip header, then deliver control message.
 	pkt.Data.TrimFront(hlen)
 	p := hdr.TransportProtocol()
-	e.dispatcher.DeliverTransportControlPacket(e.id.LocalAddress, hdr.DestinationAddress(), ProtocolNumber, p, typ, extra, pkt)
+	e.dispatcher.DeliverTransportControlPacket(src, hdr.DestinationAddress(), ProtocolNumber, p, typ, extra, pkt)
 }
 
 func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer) {
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index 3cd48ceb3..79872ec9a 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -52,8 +52,6 @@ const (
 
 type endpoint struct {
 	nicID      tcpip.NICID
-	id         stack.NetworkEndpointID
-	prefixLen  int
 	linkEP     stack.LinkEndpoint
 	dispatcher stack.TransportDispatcher
 	protocol   *protocol
@@ -61,18 +59,14 @@ type endpoint struct {
 }
 
 // NewEndpoint creates a new ipv4 endpoint.
-func (p *protocol) NewEndpoint(nicID tcpip.NICID, addrWithPrefix tcpip.AddressWithPrefix, linkAddrCache stack.LinkAddressCache, dispatcher stack.TransportDispatcher, linkEP stack.LinkEndpoint, st *stack.Stack) (stack.NetworkEndpoint, *tcpip.Error) {
-	e := &endpoint{
+func (p *protocol) NewEndpoint(nicID tcpip.NICID, linkAddrCache stack.LinkAddressCache, dispatcher stack.TransportDispatcher, linkEP stack.LinkEndpoint, st *stack.Stack) stack.NetworkEndpoint {
+	return &endpoint{
 		nicID:      nicID,
-		id:         stack.NetworkEndpointID{LocalAddress: addrWithPrefix.Address},
-		prefixLen:  addrWithPrefix.PrefixLen,
 		linkEP:     linkEP,
 		dispatcher: dispatcher,
 		protocol:   p,
 		stack:      st,
 	}
-
-	return e, nil
 }
 
 // DefaultTTL is the default time-to-live value for this endpoint.
@@ -96,16 +90,6 @@ func (e *endpoint) NICID() tcpip.NICID {
 	return e.nicID
 }
 
-// ID returns the ipv4 endpoint ID.
-func (e *endpoint) ID() *stack.NetworkEndpointID {
-	return &e.id
-}
-
-// PrefixLen returns the ipv4 endpoint subnet prefix length in bits.
-func (e *endpoint) PrefixLen() int {
-	return e.prefixLen
-}
-
 // MaxHeaderLength returns the maximum length needed by ipv4 headers (and
 // underlying protocols).
 func (e *endpoint) MaxHeaderLength() uint16 {